Dual Effect of Sulfation on the Selective Catalytic Reduction of NO with NH3 over MnOx/TiO2: Key Factor of NH3 Distribution

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• 作者：Shijian Yang ; Feihong Qi ; Yong Liao ; Shangchao Xiong ; Yi Lan ; Yuwu Fu ; Wenpo Shan ; Junhua Li
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：April 9, 2014
• 年：2014
• 卷：53
• 期：14
• 页码：5810-5819
• 全文大小：547K
• 年卷期：v.53,no.14(April 9, 2014)
• ISSN：1520-5045

文摘

The sulfation showed a dual effect on the selective catalytic reduction (SCR) reaction over MnO_x/TiO₂. The activation of adsorbed NH₃ and the adsorption of NO_x on MnO_x/TiO₂ were both restrained after the sulfation. Therefore, the SCR reaction through the Eley鈥揜ideal mechanism and that through the Langmuir鈥揌inshelwood mechanism were both restrained, resulting in an obvious decrease of NO conversion below 300 掳C. During NO reduction over MnO_x/TiO₂ at higher temperatures, there was a competition among the SCR reaction, the nonselective catalytic reduction (NSCR) reaction and the catalytic oxidation of NH₃ to NO. The NSCR reaction and the catalytic oxidation of NH₃ to NO over MnO_x/TiO₂ at higher temperatures were both restrained after the sulfation, so more NH₃ adsorbed on sulfated MnO_x/TiO₂ was used to reduce NO to N₂. Therefore, the SCR activity and N₂ selectivity of sulfated MnO_x/TiO₂ at higher temperatures were much higher than those of MnO_x/TiO₂.